Pull gun



Marh5,1946. 'H R, SCHER 2,396,001 PULL 'GUN l Filed may 5o, 1944 e sheets-sheet 2 I] n rl INyENToR Abw/m A? HJC/rfa www March 5, 1946. R. FiscHER PULL GUN esmas-sheet s Filed May so, 1944 e. i L m5 mf w 0 AT ORNEY March 5, 1946.

- H. R. FISCHER PULL- GUN Filed May 3o, 1944 e Sheets-Sheet 4 y lNvENToR /%W4/Pa ATTORNEY March 5, 1946.. v H. FISCHER l 2,396,001

PULL 'GUN Filed May 30, 1944 6 Sheets-Sheet 5 i YZO Patented Mar. 5, 1946 UNITED STATES `PATENT OFFICE Howard R. lFischer, Detroit, Mich., assigner to Chicago Pneumatic Tool Company, New York, N.' Y., arcorporation of New Jersey Application May 30, 1944 Serial No. 538,008'

(ci. 21S-19) This invention relates to power tools for pulling a mandrel or draw pin while applying the reaction to a tubular element surrounding the mandrel, and more particularly to a portable pneumatic gun for installingblind rivets in sheet metal structures. Y

An object of the invention is the provision of a riveting machine of the indicated character which is capable, a iter setting the tubular element or rivet shell, of modifying the operation and forcing an initially integral collar upon the rivet shell down into the latter within the head thereof in order to lock said shell permanently upon the mandrel, and nally breaking off the mandrel above the upset shell. Y

Another object is to have such a riveting machine which is sufficiently compact to be conveniently held in the hand and applied to the work at will, while the machine or tool as a whole has such a well designed form that it at all times provides a satisfactory visibility of the work and of the rivets being set.

A further object is to set means which include a Wedge and roller arrangement for multiplying the pressure derived' from a reciprocating piston. According to a feature a blind rivet by powerY of this invention the upper roller is connected to the mandrel to pull the latter while the lower rollers are mounted on a track which applies the reaction to a primary anvil to set the rivet shell.

A still further object is to shift the point ofV reaction automatically from the primary anvil to a vsecondary anvil which is positioned to force the vlocking collar between the rivet pin and shell. Accordingly, another feature of the invention resides in an arrangement for frictionally hold,

ing thetrack in engagement with the primary anvil until a predetermined wedging. -or setting.l

'trating the same as held in the hand of an oper.;

ator in active use;

Fig. 2 is a top plan View, partly in section of the apparatus of Fig. 1 on a larger Scale; Y

Fig. 3 is a transverse section of the tool lookingforward as indicated'by the arrows 3 in Fig.

cated by the arrows 1 in Fig. '5;

v tainer yfor the mandrel;

. Fig. 4 is another section of thetool on line 4-4 in Fig. 5 looking rearward;

Fig. 5 is a longitudinal section of the entire apparatus, showing a mandrel inserted into a hollow rivet element and gripped in theforward chuck portion of the tool and the parts of the latter generally disposed in initial position ready for operation; f Y

Fig. 6 is a front View in elevation of the pulling spindle which actuates the mandrel aforesaid;

Fig. 'l is a cross section of the tool as indi-- Fig. 8 is a detail view in section of one of the spring supporting washers;

Fig. 9 is a detail view of one ofthe spacerV rivets that hold the side arms in spaced parallel relation;

Fig. 10 is a detail view of the transverse shaft mounted between the side arms and within the roller;

. Fig. 11 is a longitudinal'section generally similar to Fig. 5 but shows the parts of the tool operated to set the rivet;

Fig. l2 is a detail view of the sleeve which carries the outer anvil; f

Figs. 13 and 14 are plan and side views respectivelyof the bushing which carries the inner anvil;

Figs. 15, 16 and 17 are plan, side and rear views respectively of the stationary .bearing member which receives vthe thrust of the track or channel bar; I

Fig. 18 is a detail view of the ratchet or re- Fig. 19 is a longitudinal section similar to Figs.

Y 5 and 11 illustrating theoperation of driving a locking collar and breaking ofi the mandrel;

Fig. 20 is a sub-assembly view in side elevation, showing a side arm, Spring supporting washer, and spring connected together;

Fig. 21 isa transverse section taken on line .2l- 2| in Fig. 5;

rFig.22 is anY enlarged scale section ofa pair of metalor other work sheets showing rivets and associated-mandrels in three stages of operation; and,` v

Fig. 23 is an enlarged longitudinal section through the cylinder casing'.

-In several types of metal structures at least ture of aircraft, the' metal sheets forming the skin of the latter have some areas which are not .conveniently accessible from otherthan the outcally follow each other in quick succession, thaty is by rst setting the rivet by' pulling upon the mandrel which extends through the `tubular element or shell of the rivet, breaking on and wedging a collar down into the rivet head about 'the mandrel and finally breaking off the latter above the rivet head, all without special attenti-on on the part of the operator.

Hence referring again to the drawings, in the practice of the invention Yan apparatus embodying the latter is disclosed `as exteriorly comprising a cylinder casing I@ forming the rear body portion thereof, with an adapter II secured thereto by screws I2 and connecting the casing with an intermediate elongated and relatively narrow, hollow grip member I3 adapted to be held in the hand as shown in Fig. r1. The intermediate elongated grip member is secured to the adapter by upper bolts or rivets I4 (one shown) and by lower rivets I5 which simultaneously hold the rear supporting block I6 in place within flange I1 of the adapter, the purpose of which block will presently be explained. At the front end of the grip member a tubular spindle casing I8 is welded, brazed or otherwise secured thereto, the grip member I3 being readily made of sheet metal bent into shape or shaped from tubing 'and the spindle casing I8 from a metal tube, while casing IB and adapter II are preferably made of cast metal such as magnesium alloy. On the-upper portion of the intermediate grip member is xed a hand stop I9 and beneath said member is secured a bracket 2I bent down at the rear to 'form a linger stop 22 and at the other end lbent down forwardly to serve as va vsupport or bearing `23 for the pivot pin 24 of a rearwardly directed throttle trigger 25. The hand stop `I 9 'and bracket 2| may be secured to grip member I3 by brazing or welding.

The stops I9 and 22 are designed to `properly ilocate the operators hand 26 (Fig. 1) vin position upon the grip member to allow .the index finger 21 to engage the trigger convenientlyfor operation. As the trigger pivots about pivot pin 24,'it is capable of longitudinally shifting a trigger `rod 28 connected to said trigger by a'trigger pin 29, occupying a bottom slot 3I and vslidably supported on bracket 2| and viiange I1, whileterminating at the rear in a hook 32 overhanging the rockable throttle cross arm 33 located within the adapter and arranged to fulcrum on the pin .34 xed in the latter and engaging the cross .arm intermediate the` ends thereof. At its outer end vthe cross arm has a recessedportion'3Eraningthe rear and receiving` one end of 4throttle push Apin 36 which at its other end directly abutsthe front end of the spindle or body portion'31 of Ythethrottle valve 38, the spindle being movably guided in .valve bushing 39 fixed in bore 40 in casing I0 and provided withavalve `seat 4I against which valve 38 is urged by valve spring 42. The latter 'ex'- tends into fixture 43 screwed into the rear of casing I0 and forming the motive fluid Vinlet port to which an 'air h'o'se 44 connected toa source 'of'fluid supply may be attached. The throttle valve spindle 31 has a neck 45 connecting the same with the valve head 38 proper. Manually depressing the trigger toward bracket 2I causes the trigger to draw rod 28 forward and rock the cross arm upon fulcrum pin 34 from the position of Fig. 5 to that of Fig. 11, while push pin 36 and valve spindle 31 are both pushed rearward to shift valvehead 33 off its seat 4I in `opposition to spring 42, which allows pressure fluid from inlet aperture 46 in xture 43 to pass the valve seat and proceed about the neck 45 and thereafter travel up -through a passage 41 opening into the throttle valve bushing 3.9. Passage 41 communicates above the piston chamber 48 with valve chamber 49 of Va slidable shift valve 50 through intercommunicating ports 5I. The valve is provided with Va pair 'of valve heads 52, 53 spaced apart and slidably mounted in two aligned valve bushings 54, Xed in the cylinder casing with a gap 56 between'them in a manner and for a reason which will presently appear.

The piston chamber 43 4contains a Yrelatively thin piston head 51 substantially consisting of a plate having a, cup leather 58 to provide a tight sliding fit in said chamber, said leather being held in assembled relation with the vpiston by a retaining plate 59 -secured to the rear of the piston bythe nut 50 screwed upon the rear end of the piston `rod 6I, the nut also serving to nx the piston rod tothe front of the piston head, so that the piston rod `willbe positively moved lonvgitudinally'bythe piston head. The piston chamber 48 is provided rearwardly with a projection 62 serving as a stop to 'limit rearward movement 'of thepiston and insure that a predetermined space 'will be presented behind-said piston for introduction of pressure iiuid to operate the latter. When the trigger is operated t-ointroduce pressure fluid into shift valve chamber 49 through passage Y41 las already outlined, valve 5I] `iirst occupying the extreme rear position vof Figs. 5 and 2B, the fluid immediately passes from valve chamber 49 Vdown through kgap 58 `into lpiston chamber y48 `rearwardly of 'piston 51 and drives thelatter and piston rod 6I forward for initially setting la, rivetgenerally indicated at y63, Awhich is thereafter further set and iinally finished and parted Afrom the device, as will `be described in detail.

Leaving the piston and valve control therefor forthe time being, attention is directed to the forward end of the piston rod and the apparatus'as a whole. ,'The piston rod has a self-adjusting or `self-aligning connection vlill with an operating wedge 65 mounted to ride upon a series of roller bearings 86 retained inoperative association by a roller bearing cage 61 and rolling upon a lower channel-shaped arm or track Ymember "58. The bearing ycage terminates rearwardly in apair of hooks `69 (one shown) projecting upwardly between studs 1I extending to both Vsides of piston rod 6I vand the side studs '12 'extending inwardly from the side walls of the Ychannel-shaped track'member in order to insure that the cage with its roller 'bearings will `constantly 'follow the movements of the wedge and maintain the roller'bearings in vproper position beneath the same. The rear end of the track 70 member rests .slidably ,on the previously mentioned support block 'I6 .and is provided with a reduced or'limitediulcrum edge 13 to allow rocking thereon involving a .slight ,raising and 'lowering of the forward end`14 of said member in a manner peculiar to the invention.

At the sides ofthe wedge are located a pair of side arms 15 (Fig. 7) secured together in mutually spaced relation by a plurality of spacer rivets 16 (Fig. 9), and intermediate kthe ends, said arms are provided with a transverse shaft-11 (Fig. 10) forming an inner race for a group of roller bearings 18 upon which a roller Y19 is rotatably mounted in a positionY adapting this roller to be engaged by the wedge 65 and raised thereby when the wedge travels in the forward direction. Rear- Iwardly the side armsl are pivoted o-n two' bush-l ings 8| which are supported on' transverse bearing shaft 82 fixed in the adapter II,l with the ends extending through the sides of the latter and exteriorly thereof having resilientretaining rings 83 seated in grooves 84 (Fig. 21) retaining the shaft in position in order forl said shaft to form a very stable fulcrum and point of reaction for certain of the interior operating parts of the apparatus, and to be accessible fromthe outside to facilitate assembling and disassembling the apparatus. Within the spindle casing I8 the front ends 85 (one shown) of the side arms engage in the side recesses 88 (Fig. 6) in the head 81 of a pulling spindle 88 whose upper end terminates ina reduced tubular portion 89. To the latter is connected the lowerend of a coiled metal strip or volute spring k9| Secured within the upper end of the spindle Vcasing by a retaining ring 92 and serving as an ejector chute for broken rivet mandrels cast off during operation. The spindle is hollow throughout and extends down wardly to form a continuation-of the ejector chute, having a lower threaded hub 93 and terminating below the latterin a reduced hollow 'their inner gripping, sides I|6`toothed to t the serrations-IH of the mandrel (Fig. v22) in order to prevent slipping of the mandrel out of the chuck. Moreover, within said chuck is a follower ring |I1 pressing on the jaws 91 under the bias of the follower spring |I8 surrounding the lower reduced end portion 94 of the spindle, allowing the endV of the mandrel to be thrust upwardly between the jaws which spread open to accommodate the same, until the nal position of the y mandrel is reached, whenv the spring urging the ring-downward will thereby tend to close the jaws upon said mandrel. The mandrel proper fits slidably into the inner anvil |08 above the blind rivet 63, with the rivet head H9 normally drawn up against outer anvil |02, while the upwardly projecting collar I2 I, Ypreferably integral with the head projects up into the outer anvil agains yfrom turning or being displaced by a plug or screw |24 extending into lthe same through'the frontv wall vvof the spindle casing, said bearing member being provided with a seat |25 forming the actual front support of the lower arm 68. Beneath the forward end 14 of the latter, but rearwardly of seat |25 is a flange or reinforced Yportion |26 forming the upper end of the inner end portion 94, a chuck 95V'being screwed upon hub 93 against spindle shoulder 98 above Vthe thread and provided with the chuck jaws 91 cooperating with the conventional'inner tapering chuck walls 98 thereof to grip the upper serrated end of a rivet mandrel or pin I0|.f `The latter is brought into po-sition by inserting said serrated end first through fixed outer anvil |02 screwed into the rigid lower end |83 of the stationary outer anvil sleeveor thrust bushing |04 (Fig. l2) fitted into the spindle casing I8 with the lower end of the latter abutting the flange |05 of sleeve |04, while a further flange |06 on said anvil sleeve, located in a recess |01 in the spindle casing serves to retain said "sleeve in place.V The upper portion of sleeve |04 is slotted to enable the flanged or beaded end |06 to enter the spindle casing I8 during assembly and to spring outward when it attains its operative position.

Within the outer anvil is fitted an inner anvil |08 through which the mandrel is passed and thereafter the latter is inserted through inner anvil thrust washer |09 and through lthe mandrelratchet or retainer III (Fig. 18) immediately above the washer which is Yadapted to engage.

above said washer, the latter bushing being sur-V mounted and operated by the main inner anvil sleeveor thrust bushing I |5. The anvil |08 and vthe bushings I I4 and I I5 combine to forma-spindle member slidably mounted'within the spindle casing I8, |04 and operated independently of the chuck into the jaws 91 of which the mandrel is inserted.` The mentionedjaws of the chuck have anvil thrust bushing |I5 which is disposed in appropriate position to receive the end of the mentionedl lower arm whenever the same is withdrawn from stationary seat |25 by a rearward movement of said arm. The means for 'thusr shifting the arm in proper order with preceding pulling of the mandrel and setting of the' rivet will now be considered.

Y Upon one of the bushings 8| which forrnthe return spring |32.

pivoting center for the upper arm 15 is mounted a shifting lever |21, having a downwardly projecting lug or linger |28 extending into a vslot or 'recess |29 in the rear portion of the lower shiftable arm 88, so fthat'when the lever'is swung counterclockwise, the finger |28 will shift lower varm 68 correspondingly rearward. vThe upper end of lever |21 is pivotally connected by a pin II0` to a `clevis or connecting link |30 having Ya nut I3I screwed upon one end of the link and being flanged for engagement with a shift lever 'spring sleeve I 33 fitted into counterbore inA the upper part -of casing I0 and abutting the adapter II'so as to prevent displacement ofthe vrsleeve.V` The sleeve is provided ywith inwardly projecting lug I 35 serving vas an end stop for spring |32 in order to allow compression of said spring toward said lug by the Yshift lever with simultaneous longitudinal shifting of lower arm 88, such compression of the spring causing 'it to is moved forward. Between the latter valve and then'ut is mounted a shift valve spring |38 tending to cushion contact between the valve and nut and begin Yto exert pressure against the nutwhen the valve is first caused to move toward the'same.

The latter is located withiny i geth er.

up behind said lpiston to a vhigh level.

`valve cap |58. fdiately shift the lattervalve from theposition of :n has'aiready beenimentionedanat wnentne ;trigger'25 is pressed toward thegrip member .I3

ythe Vthrottle valve -3'3-opens, with the `result that pressurenfluid from'inlet port 45 will travel up :through passage 41 into upper valve chamber 4S `'and lthence through gap 55 down behindfpiston Y51,-olriving the-latter forward. If thenthe-man- '.85 of said arms engage in the spindle recesses 8B.

the Yarms will correspondingly raise spindle 88 zandchuck 95, and the mandrel IIlI will be kdrawn -upwardwhile the'head I I 9 of rivet 63 is held stationary against anvil yIt? until the head |39 of :themandrel is drawnup into definite contact with rivet shell |4I. The piston fthen continues -to;force the wedge forward and the mandrel vwill .beginito exert sufcient pressure on the shank end -of the rivet shell, due to the powerful pull :of the upper arm 15, 85 and of the spindle 88 to labuclile or bulge the shank as shown at |42 in Figs. l'111, 19 and 22. As best Jseen in Fig. 22, the second mandrel and rivet shell appear in en- 'largedfform in the same stage of operation as in Fig. ylland in proper relation to-a .pair of work sheets-|43, |44 which are intended to be riveted to- In this Figure 22, it is clearly evident that themandrel has a `locking groove or recess 145 spaced a short distance from the head |39 land immediately-above the groove'is arib v|46 of equal diameter with the mandrel shank |0| genpressure fluid continues to flow to the rearpor- `tion of piston chamber 48 through passage 4.1,

-although without furthereiect on the piston, it -is self-evident that the pressure willtend to build In the "rearof Vthe cylinder casing isa relief valve |48 normally held against valve seat r|49 in a xed kvalve'bushing |51 (Figs. l1, 19 and 23) by spring |52 within pressure adjusting screw |53. This screw by manipulation serves to adjust the 4pres- :sure :at which the spring .willallow the valve to itained or adjusted position. When the pressure in the rear vof the piston becomes sufficient to vopen the valve'by overpoweringthevalve spring, the pressure-fluid in the vrear-.piston chamber'will fpass `into relief vvalve chamber |56 and travel 4up 1 through passage 51 into the rear Yshift'valve :chamber .49 in bushing 4 to the rear of valve head 52 of fshift 'valve 50 v'and `within the A,closed The `pressure 4iuid :will imme- Figs. 5 and 23 a short distance in the forward direction to 'an intermediate position in which the 'front end |31'of said valve abuts the rear end of linknut |3| and occupies the position illustrated in Fig. 1l, wherein valvehead 53 has uncovered rfmain exhaust passage I 59 and :connects the :in-

terior of the rear pistonechamber Vto atmosphere .through the latter causing spring 16:2 to force piston 512torits rearward `position;v and gpermitting spring |52 to'rseat valve |48 to entrap highpres- :sureair-in-backof valve5. VA-shield IBD-isse- -cured'by -screws |6| (Fig. 23) or other meansfto the exterior vof casing I0 `to deflect the issuing .spentfpressure fluid rearwardly inorder to avoid annoyance to the operator.

-As Wedge 65 starts to recede upon the'open- ,ing of exhaust port |59, its pressure against arm 68 is relieved, since the partiallyupset rivet Yand spring ||8 hold arms 15 in their elevated riposi- '.ion, and air pressure back of valve v5||fcauses the 1 1 to ,that of Fig. 19 it uncovers small ports |63 and closespport 5| which-formerly communicated throughport with the vback of piston Y51. Upon the uncovering of ports |63, live :air lpasses'from'rpassage 41 through grooves `|64 and ports I-|53to theback of valve v52| 'thus continuing ,the forward motionfinitiated bythe high-pressure `airoriginally trapped back of Valvef5. As-the valve 58 moves farther forward portion 52 `enters sleeve .55 thus in'effect closing exhaust |59. :As valvefEEl moves farther forward it opens port L56- and is forced to the extreme `forward position shown in Fig. 19.

vIn the newly attained position, the shift lever |2-1 by means ofthe lower end or finger |28 Vhas .drawn the .lower arm58 rearward a suflicientdistanceto removethefront end 14 fully from off the stationary-seat |725 and exclusively'upon the ange i525 `of thrust bushing H5 of the inner anvil. rThe shift Valve by its rear valve head lhasnow also covered the exhaust port |59 land again opened ports 5|, allowing pressure fluid to kflowin through valve chamber 48, and by `way :of gap 56 into the rear `piston chamber again to drive the lpiston with its piston rod and asso- 'ciated wedge forward. Due to thefshifted posihtion of valve.5|l the relief valve will no longer :act -to limit the operation of the piston las it is exposed to pressure on both sides. Tension will thus again be applied to the vmandrel rby the renewed raising or `pulling `movement'of spindle 38 and-its associated chuck, but in this instance the downward pressure exerted bythe wedge throughroller bearings istransmitted by the frontend -14 of the track member or lower arm 468 solely to the `thrust bushing -||4 provided Vbelowfwith the anvil thrust washer' |09 directly engaging against inner anvil |08, which vin turn abutsthe upperend of integral collar iffi en vthe rivet shell. With the entire pressure of thein- -ner anvil exerted upon said collar while vthe yrivet'isgpowerfully held with its head I9 against iouteranvil |02, andthe pressurenow being capableof rising to any desired `height because the relief valve Yis disabled, the pressure upon collar |2| is soon so great (Fig. v19) that itabruptly kbreaks loose from head I9 and is Aforced Vdown finto the hollow portion |65in the rivet head and the corresponding locking groove v|45 in the .mandrel to become firmly fixed therein as shown 'or fractures in the breakneck portion |41 vim- ,mediately-above the rivet headand lthe mandrel l-rib |4B, leaving^the lower end IUI) of ythe mandrel to the same or to portions of the cylinder casing,

the piston return spring |62 engages against the plate |61 having a shock absorbing rubber or other resilient ring |68 secured by any suitab-le means in the cylinder casing. Thefracture of the mandrel which immediately frees the tool s Y (Figs. 2V, 3, 5.11 and 19) secured thereto by the endv |80 extending through link slot |62 and the Y link seated in recessed portion |83 of the spring.

from the work is at the same time the signal for the operator to release the trigger and shift the apparatus to a new rivet hole with a new mandrel and rivet shell inserted and held by the chuck, the insertion of the new mandrel causing the chuck to release the serrated cast-off stump n of the old mandrel and allowing the same to be pushed up through the hollow spindle toward the ejector chute 9|. When the new mandrel with its mounted shell is in position, the apparatus is rimmediately ready for a new cycle of operation automatically carried through by the apparatus itself upon merely rpressing the trigger and holding the same until the cycle is l completed. v Y

When the trigger is released, the throttle valve Y is closed by being shifted forward by spring 42 so that neck 45 of the'valve is exposed to the Y throttle exhaust port |69, which allows free escape of pressure fluid from passage 41 through said exhaust port, thus clearing the piston chamber of` pressure fluid, and this circumstance permitting the. spring |82 to return piston 51 to initial position against rear stop 62 and springs |32 and |38 to return shift Valve 50 to extreme rear position. As soon as` rear valve head 52 in movingrearward kcloses ports 5|, the residual l fluid in rear valve chamber 49 and passage |51 is prevented from being trapped in said chamber in a mannerrwhich might prevent full return of the valve, by escaping' through the small ports |63 communicating through passages |64 with passage 41 until valve head 53 covers said small ports. Then the remainder of the fluid inthe last stage of thereturn movement of the valve escapes through'a rearwardly open longitudinal passage 1| inthe Valve (Fig. 23) communicating through passage |12 in said valvehead, with peripheral groove |13 during said movement registering'with main exhaust port |59 and releasing the final residue of pressure fluid to atmosphere which frees the Valve so that it may return to make contact with valve cap |58. Y

While the piston and valves return to initial positions, the wedge is also withdrawn rearwardly to remoVeally operative pressure from beneath roller 19 and from lower arm or track member 68. In order for the front end of the latter to be capable of resuming its position on seat |25 when the lower arm isy shifted forwardY by clockwise movement of shifting'lever |21, a pair of .springs |14 lare mounted exteriorly of upper armsr15, each being rearwardly looped about a supporting washer |15 (Figs. 8 and 20)v secured by a screw or rivet |16 to its respectively adjacent upper arm. with the short leg |11 of each spring confined against a stud or screw |18 upon the same upper arm. A spacing sleeve |19 (Figs. 2 and rI) surrounds the krivet |16 and co operates with yspacer rivets 18 and transverse shaft 11 to maintain the side arms 15 in parallel relation. The relatively longer upper leg of each spring extends forward over the sides of lower arm 68'and at its front end |80 has a link 8| At the Abottom the springs are hooked from beneathintoapertures |84 inthe forwardiy di-` rected projections' |85 upon said lower arm. The Vtwo springs together tend to raise the arm as soon as thestrain of the wedge is removedl by the Wedge being freed from operative contact with roller 19 so that the `lower arm will'imme-` diately be raised to the level of the mentioned rseat 25 lfor restoration thereto.l In order to maintain said lower arm within operative bounds, the forward shoulders |86 thereof form upper limiting edges adapted to engage against the foremost spacer rivet 16, while at the rear thependent lugs |81 upon upper arms 15 extend down to within a slight distance from the lower y arm andV prevent the same fromjumping oif the support block |6. In addition the latter block terminates ina rear stop |88 serving to prevent undue rearward displacement of said lower arm.

Also inconnection ywith ther inner anvil thrust bushing, the upper reinforcement or flange |26 is limited in downward movement asa precaution by the rearward projections |89 integral with the stationary bearingmember |22 within the spindle casing, Vso that even if the inner anvil should break, crumble or be missing, the thrust washer Vlill) will be-prevented from striking anvil |02. In order to facilitate operation and allow access'to the inner anvil as well as to insert the outer anvil and even have access to the thrust Washer,`retainer as well as thevchuck, the spindle ycasing has a forward cut away portion |9| (Fig. 1)v exposing thrust bushing ||4 and portionsrof the mentioned parts. This cut away portion also gives access to a broken mandrel or f part incase the same becomes stuck in the chuck and the latter or any other part requires special attention during operation, On the other hand, the cylinder casingv has a rear screw plug |92 which may be removed for inspection and lubri cation of the piston, when desired.A f

From the above description it might seem that one kcomplete cycle of operation wouldV extend over a considerable period of time. The actual ltime consumed,however, in a commercial embodiment of the inventiornfrom the instant the` triggerispulled, until the rivet head is formed,

' mandrel locked in place, mandrel broken, trigger released and all parts returned to their normal position, is only about one second.

n While the/invention has been described with particular reference to the art of setting blind rivets; it should be Vunderstood that the invention, or at least certain features thereof, are applicable for other uses such as dimpling, grommet setting, attaching hooks or, shelf brackets to sheet metal walls, andestablishing pin-to-plate connections generally. Y

What is claimed is: Y

V1. Apparatus forsetting arivet assembly of the type rincluding a shell and a lpin extending through the shell for upsetting the latter at one Y side of a structure, said apparatus comprising a stationary anvil constituting a stop for the shell i holding the latter in'positionl during operation, a movable spindle member having means for gripping Vthe pin, actuatingv meansv for moving the spindle member and subjecting the pin to tension, axedsupport, a second movable spindle member having a portion for engaging a portion of the shell to apply pressure thereto, a shiftabley member disposed in position for receiving the reaction of the rst spindlemember. when thelatter. is. operated by' saidl actuating means, said shiftable member having a portion resting on the fixed support` when a predetermined.. tension is. applied to the pin. toupsetthe shell. againstthe side of the structure, and means for shiftingsaid portion of the shiftable. member off the fixed support and upon the second spindle member and.

spindle member to move the latter and thereby-l subject thepin to tension, a fixed support in said apparatus, a second movable spindle member having anV anvil portion for engaging a portion' ofA the shell to apply pressure thereto, a movable powery driven wedge adapted to engage with a portion uponsaidmovable arm in-order tomove the A.latter andthereby also'the spindle member, aA shiftable second armV constantly supporting said movable Wedge in all positionsof the latter and having one end adaptedto rest on the fixed support inorder to allow thewedge toactuate theA movable arm and operate the first mentioned`v spindlemember and thereby subject the pin to suflicient tension to operate the shell, said shift-- able second arm being. effective when the men-- tioned one end thereof rests on'the second spindle member to cause the anvil-associatedwiththe latter tov apply. pressure tothe shell, automatic.

means for shifting said-second ar-m frornvoff said fixedsupport and upon saidsecond spindle' when theishell-hasbeen. upset, and means for controllingtheoperation of said wedge.

3. Apparatus for. setting a blindrilvetvaccording to .claim 2, in whichthe arm means includesa pair ofE corresponding. arms disposed at the sides of theshiftable second arm, andin which resilient means are included tending to support said-shiftable armin. raised position.

4'. Apparatus for setting-a.blindrrivetshell-having ahollow shank terminating in aheadat .one end, withi the aid of a mandrelinserted in said rivet shell and provided with a head-exteriorly of theshank of the rivet shell, including a casing having a. cylinder containing a reciprocable pisi ton., arigid primary anvil upon the casing for en-v v gaging. against the head of the rivet shell, operable means having facilities for gripping the shank of the mandrel beyond the headl of: the. rivetshell and movable with respect to the anvil.

in order to pull upon said mandrel torapredetermined extent while the rivet head isheldagainst the anvil, driving means actuatedby saidpiston during` the working movement thereof effective to Vcause theV pulling movementV of said operable means to set the riveti shell, further operable means including asecondary anvil capable of engaging independently against a portion'upon said; rivet shell, a shiftable member cooperating with.`

said. driving means, an unyielding support for.

eachend of said shiftable member in said casingz.

and automatic means. effective uponk setting. .of

the rivet shell toshiftoneen'd' of theshiftabley member off its Asupportxuponaportion of thefur.-v ther operable. means while. the. other end: of: said'.

zgaaaoor shiftable member` remains on-it'ssuppor-t; Where'- by the reaction of; the* pullf. on the mandrelY is'- taken off the. primaryv anviland transferredto the secondary anvil@` 5.. Apparatus for setting aiblindi rivet accord:- A ingto claim-4 in whichtheautomatic means in'- ciudes a uid operated lever connected tothe shiftable member toI shift the latter andv has ai. Valve controlling the flow of' pressure fluidi for.V causing operation of. said: lever whena predeter minedi high pressure'ofv fluid hasv been: attained? in the piston chamber: of the cylinder.

6; Apparatusv for.` setting a. blind'v rivet'A having at hollow shank. terminating in. a headI atf one end; with the: aidof a: mandrel inserted in:` said?- rivet. andLpi-ovided Withla headl exteriorly of. theL shank. of theyrivet, including: a casing having a cylinder. containing: a: reciprocable piston,V an..

inlet port for admitting pressure fluidY intoy the:`

cylinder to propel the pistonin at leastlthe-working direction from an1initia-l position a .rigidi anvil upon the. casing engageable ag-ainstthe. hea-zi'. of therivet, a spindle-reciprocably mount-- edY in.. aportion of? saidl casing. having a. chu'clrA for gripping the shankiofthe mandrel.- beyond'.

the head of the rivet, arm meansl pivotall'y mounted? in. the casing. with one end thereof engaging' with saidv spindle'v and effectivey to: raise thelatter, a shiftablev armi also disposed within:l said casing, anunyielding supporti-fon eachendl of said shiftable. armg. ani independently. recip rocabie spindle member.: mounted'.l adjacent to: saidV spindle andi having.' a. movable". anvil. mem

ber associated therewith in effectivev position` f, tor engage against: a locking' member uponv thev rivet head; rollermeans mounted upon.- said first'- mentioned arm means, a. Wedge member! connected to the pistonto, be moveditherebywhile' riding on the shiftable armgwith the latter serv.;-l ing as a .stationarytrack;therefor' andwhile said..

wedge member engages withlsaidlroller means-1to1 raise the first mentioned-1 arm. means. during.

working movement of: said? piston. andi wedge memberV in. order to cause the :spindle yand chuck' torise. and pullv upon-.theA mandrelA` and therebyV set the rivetW-hilei holdingfthehead of therivet' against-theA rigid anvil; a: shifting. lever. pivotally mounted in association with saidv casing.; and'. having. one. end. connecte'di to saidl shiftablei arm, a.. fluid; operated' piston valve: capable. off operat'.- ing saidY shifting. lever. in. onel directionz to' effect shifting of` saidshiftable arm: to; remove. onefende thereof from its .supportiY upon* saidindepend.- ently reciprccable spindle,` member; while: the other end'v of: said shifta'ble armiVx remainsr on"V its support, andY a. relief i valve communicating: with thepistcn: chamber. controlling theizflowfof presi,- sure Auid from said inlet portxto-said. fluidioper.;A ated piston 1 valve and? allowing; pressurev fluid to; operate` ther latter upon-attainment. of; aprede` termined high pressure: inl the: piston: chamber.

when .the rivet'` has been set.

'7. Apparatusy for. setting-a blindfrivetzaccordf ing to claim- 6 in'-` which resilient meansA are; in

eluded. tending.. to raise.; the; Spindler and; further.

.'- from the,uidaactuatedzpistcmvalve; in initial? pu;-

sition ofthev latter to provide a lost motion interval between the initial movementof said pisingjspindle tooperate .the same, said lever havprimary anvil and a secondary anvil, said anvils being disposed ccaxially with each other and arranged to engage different portions of the shell of the rivet, a cylinder'providing a piston chamber, a uid pressure operated piston reciprocable' in the cylinder, a pair of complementary pulling and pushing elements, the pulling element having a chuck adapted to grip the pin and the pushing element being adapted to abut against the primary anvil and theV secondary anvil in succession, and power transmitting means operated by the piston for imparting relative motion between said complementary pulling and pushing elements at a pressure substantially in 'excess of the force acting on the piston.

10. A power operated tool for upsettinga blind rivet of the pin and shell type comprising a chuck adapted to grip and pull the pin, a primary anvil and a secondary anvil arranged successively to abut against different; portions of the rivet shell to apply the reactive force theren to as the pin is being pulled, a power driven piston having Aan extension operatively connected to the chuck to impart a pulling motionV thereto, a track over which the piston extension rolls,

said track being arranged to receive the reaction of the piston extension, said track having a portion resting on the primary anvil and being shiftable to cause said portion to rest on the secondary anvil.

l1. A power operated tool according to claim 10 which comprises means for automatically shifting the track upon the development of a predetermined pressure in back of the piston.

12. A power operated tool for upsetting a blind rivet or similar structure of the type consisting of a pin and a surrounding shell; said tooloomprising a chuck adapted to grip and pull the pin, a primary anvil and a secondary anvil arranged successively to abut against different po-rtions of the shell to apply the reactive force thereto as the pin is being pulled, a lever operatively connected to the chuck to pull the latter, aroller carried by the lever, a power driven'wedge for actuating the roller, a track on which the wedge is mounted for reciprocating motion, said track being arranged-to seat selectively on the primary anvil and the secondary anvil to transmit the reactive force of the wedge against the shell as the pin is being pulled.

13. A portable power opera-ted tool comprising a cylinder forming a piston chamber, a fluid pressure operated piston reciprocable therein, a forward extension on said cylinder forming a handle grip member, a spindle casing secured to the front end of the grip member and extending downwardly therefrom, an anvil secured to the lower end of the spindle casing and adapted to abut against a work piece and being perforated to permit the passage of a mandrel therethrough, a pulling spindle mounted for reciprocation in the spindle casing, achuck carried by the pulling spindle and having jaws arranged for gripping and pulling the mandrel, atrack mounted in the cylinder extension and having an end supported on the spindle casing, a piston Vextension supported on the track for forward and rearward rolling motion, and a lever connected to the pulling a. roller interposed in the path of the piston extension, the associated surface on Ithe piston extension being inclined to form a wedge, whereby forward movement of the piston is effective to-.pull the spindle andchuck upwardly while applyingthe reactive force to the trackand anvil, and means responsive to the development f of a predetermined pressure in back of the piston to shift the supported end of the track off the 'spindle casing, thereby relieving said anvil of pressure. Y

14. Apparatus for applying pressure successivelyy to two portions of a workpiece with the aid of a mandrel inserted through said workpiece and provided with a head exteriorly of the workpiece, including a casing having a cylinder containing a reciprocable piston, a rigid .primary anvil uponV the casing for engaging against one portion of the workpiece, operable means having facilities for gripping the shank of the mandrel and movable with respect to the anvil in order to pull upon said mandrel to a predetermined eX- tent while the workpiece is held against the anvil, driving means actuated by said piston during the-working movement thereof effective to cause the pulling movement of said operable means to deform the workpiece, further operable means including a secondary anvil capable of engaging independently against a second portion of said workpiece, a shiftable member Acooperating with vsaid driving means, an unyielding support for each'end of said shiftable member in said casing, and automatic means to shift one end 0f the shiftable member oi its support upon a portion of the further operable means while the other end 0f said shiftable member remains on its support, whereby the reaction of the pull on the mandrelis taken off the primary anvil and transferred to the secondary anvil.

15. Apparatus for deforming a workpiece with theaid of a mandrel inserted through said workpiece and provided with a head exteriorly of the workpiece, including a casing having a cylinder containing a reciprocable piston, an inlet port for admitting pressure fluid into the cylinder to propel the piston in at least the working direction from an initial position, a rigid anvil upon the casing engageable against a portion of the workpiece, a spindle reciprocably mounted in a portion of said casing having a, chuck for gripping the shank of the mandrel, arm means pivotally ,mounted in the casing with one end thereof engaging with said spindle and eiective to raise the latter, a shiftable arm also disposed within said casing, an unyielding supportV for each end of said shiftable arm, an independently reciprocable spindle member mounted adjacent to said spindle and having a movable anvil member associated therewith in eiective .position tol engage against `a second portion of the workpiece, roller means mounted upon said rst mentioned arm means, a Wedge member connected to the piston to be moved thereby while riding on the shiftable arm with the latter serving as a stationary track therefor andy while said wedge member engages i Y with said roller means to raise the rst mentioned 8 'afsaemm piston vvaivecapableof `operating said shifting lever in one direction to eiectshiftingof :said shftable arm to remove one end `thereofyirom its support .upon 'said Y ilodependerl'oly1 reepro cablespindle member Whilerthe otherfend ofxsadshiftable larm remains on itssupport, :andi a relief valve communicating with -the ypiston chamber 

